Thirty years after the Sugarhill Gang's Rapper's Delight became the first mainstream rap song to hit the US charts, how and why has hip-hop spread to different parts of the world?

Public Enemy rapper Chuck D famously once said rap was "CNN for black people".

In the years following its emergence in 1970s New York, hip-hop culture has manifested itself around the world - most notably in the many rap acts that now exist across the globe.

Ben Herson is founder of the Nomadic Wax record label

Ben Herson is the founder of fair trade record label Nomadic Wax, which is committed to bringing acts from developing countries into the wider public consciousness by distributing music online, pressing records and making documentaries.

He argues that Africa is the true "birthplace of hip-hop".

"It travelled through the transatlantic slave trade to the US, via the Caribbean - that's what created this culture," he says.

"Hip-hop is the missing connection between the US and Africa. It's about a conversation within the African diaspora. There was Creole culture, the blues, jazz, rock'n'roll and it has become hip-hop."

Mr Herson is particularly interested in the "CNN" factor, whereby "music affects politics and affects social change", meaning that people from all around the world can relate to rap.

"Hip-hop, at its most basic form, reminds people across the world of a poetic culture. Most cultures have an oral poetic tradition."

Please turn on JavaScript. Media requires JavaScript to play.

But Mr Herson is right to point out that it has taken off across Africa in particular, in many styles.

Sudanese rapper Emmanuel Jal, for example, has risen to prominence in world music for work that draws on his experiences as a former child soldier.

In Ghana, hiplife - a blend of west African highlife and hip-hop - is ubiquitous in nightclubs and bars, while Senegal's rappers have a reputation for political commentary.

Rap has been used as a powerful political weapon by Senegalese youth - most notably in 2000 when politically charged songs that were highly critical of the government received regular airplay on a popular radio station.

These protest songs are thought to have played a part in the then ruling party losing that year's national election.

It's one of the most important tools in music nowadays because it's the only type of music talking about reality and connected to the people

Mahmoud JreriRapper

"In 2000, rappers spoke about how we could change the nation. People understood and we changed the government. Until we spoke people didn't believe this could happen," says Baay Bia, a 32-year-old award-winning rapper from Dakar.

The artist, who has had three albums and largely focuses on what he sees as the repeated failings of African governments, says he wants to "inspire" people.

"I chose hip-hop to express myself - it gives me more detail in my music and message. If I was just singing I wouldn't be able to share all I wanted to say."

The rapper, whose real name is Birane Diouf, raps in Wolof and says this style of music is so popular in his country because it is "something familiar", since it chimes with the griot tradition of storytellers and praise-singers in the country.

Using rap to carry political and social messages is not a uniquely Senegalese, or even African, phenomenon.

DAM, a Palestinian hip-hop group consisting of three members, rap in Arabic, Hebrew and English and have been active since 1999. And they're just one group in the Middle East's burgeoning hip-hop scene.

Group member Mahmoud Jreri recalls there being no hip-hop scene in Israel when he was growing up.

He says he "felt connected" with American rappers like Tupac and Nas, who he saw in music videos of the late 90s, because "they were talking about social and political problems" and, like him, seemed to live in poverty.

Now the group says there's a big hip-hop scene in the West Bank and Gaza.

DAM's lyrics touch on issues from the Palestinian situation to women's rights in Arabic society.

The theme of rap as a medium for protest recurs again in France, where hip-hop is seen as one way that the immigrant population in the suburbs express discontent.

But, just as US rappers often court controversy, rap in France - has its critics.

Nineties rappers like Tupac Shakur influenced artists worldwide

In 2005, about 200 MPs urged the country's justice ministry to prosecute seven rap groups over allegedly provocative lyrics, following claims by some political figures that rap music fuelled suburban rioting in France.

In one particularly controversial song, entitled FranSSe, rapper Monsieur R called France a prostitute. The artist said it was a diatribe against French leaders who had neglected ethnic minorities, not an attack on France in general.

And earlier this year Orelsan, a 27-year-old rapper from Normandy, saw 10 of his concerts cancelled after former Socialist presidential candidate Segolene Royal and other politicians complained that his lyrics encouraged violence against women.

A political row over censorship ensued after Ms Royal threatened to withdraw the public subsidy from a prestigious festival, Les Francofolies in La Rochelle, in her capacity as head of Poitou-Charentes regional council.

But why has this style of music, and the culture it engenders, taken off all over the world?

"It's one of the most important tools in music nowadays because it's the only type of music talking about reality and connected to the people," says Jreri.

The Palestinian rapper thinks the music's appeal is that it gives a voice to outsiders.

"It has started to be one language of the minorities. One language of the people who wanted to express themselves and describe the situation that they are living in - talking about political, social and personal issues."

Meanwhile, Herson says rap's simplicity is the key.

"It's the most basic form of music. All you need is a beat and a voice.

"If you want rock and roll, you need money for instruments. With hip-hop you can bang on a table and rap. In its rawest form it's very easy to make."

This page is best viewed in an up-to-date web browser with style sheets (CSS) enabled. While you will be able to view the content of this page in your current browser, you will not be able to get the full visual experience. Please consider upgrading your browser software or enabling style sheets (CSS) if you are able to do so.